Submersible chamber



Sept. 8, 1959 Filed Oct. 28, 1952 FIG.I

E. L. NEWELL ETAL SUBMERSIBLE CHAMBER FIG.3

4 Sheets-Sheet 1 INVENTORS E L. NEWELL P. H. WELLS C. H. CRAMER I Z! 777 LZTTORNEY Sept. 8, 1959 E. L. NEWELL ETAL 2,903,500

- SUBMERSIBLE CHAMBER Filed Oct. 28, 1952 4 Sheets-Sheet s FIG.6

I Win 7 O H! v 23 /"AMPLIFIER FIG.7

INVENTORS E. 1.. N swzu. P. H. WELLS c. H. CRAMER ATT RNEY p 8, 1959 E. L. NEWELL ETAL 2,903,500

SUBMERSIBLE CHAMBER Filed Oct. 28, 1952 4 Sheets-Sheet 4 56 86 FIG. 8.

as u 59 l 5 7 ill INVENTORS E.L.NEWELL P. H.WELLS BY C.H.C RAMER ATZ'QRNEY United States Patent "ice SUBMERSIBLE CHAMBER.

Earl L. Newell and Philip H. Wells, Chatham, NJ., and Clitford H. Cramer, Great Neck, N.Y., assignors to The Western Union Telegraph Company, New York, N.Y., a corporation of New York Application October 28, 1952, Serial No. 317,278

12 Claims. (Cl. 174-12) The present invention relates to submersible chambers suitable for extended operation under relatively large hydrostatic pressures and more particularly to submersible chambers containing electronic apparatus and arranged to provide an internal pressure substantially equal to the external hydrostatic pressure.

This application is a continuation-in-part of our copending application Serial No. 229,192, filed May 31, 1951, now abandoned; the instant application being for the purpose of setting forth additional new discovery in respect to submersible chambers when operation of the same is contemplated in much greater depths of water, as has proved advantageous, for example, in locating repeaters near a point where submarine cables cross each other, as later explained.

As described in the copending patent application of H. F. Wilder, Serial No. 229,146, filed May 31, 1951, many advantages are secured by providing a repeating amplifier in a submerged portion of a submarine cable circuit. Since electronic apparatus suitable for use at the low frequencies normally employed in telegraphic communication over submarine cable circuits is inherently bulky, it is impractical to provide a housing for a submerged repeating amplifier which will maintain atmospheric pressure at substantial depths. More particularly, it would be very diflicult to provide a relatively large container for unattended installation over a long period of time and which would maintain a high externalinternal pressure differential. For example, a typical repeater installation might be at a depth at which a hydrostatic pressure of 750 pounds per square inch would be encountered. Accordingly, the housing should have an internal pressure substantially equal to the external hydrostatic pressure.

Since it is not possible to operate electrical apparatus in sea water, the repeater housing should be filled with an insulating fluid such as oil. Delicate electronic components, such as vacuum tubes, may be encased in small sealed containers located within the housing and being designed to maintain substantially atmospheric internal pressures. A pressure equalizing mechanism must be provided to transmit to the insulating fluid the increasing hydrostatic pressures encountered as the repeater is lowered. The equalizing mechanism must also provide a reservoir to compensate for voids within the repeater housing resulting from incomplete filling thereof and for decreases in fluid volume with the temperature drop.

Bellows arrangements have heretofore been used to equalize the internal and external pressures of a submerged casing. However, arrangements heretofore employed have not been suitable for unattended use over long periods of time in deep salt water. Corrosion and mechanical failure of the bellows tend to admit sea Water into the interior of the casing. Moreover, a small amount of seepage over a long period of time will permit enough water to enter the casing to seriously damage the equipment therein.

Accordingly, it is an object of the invention to pro- Patented Sept. 8, 1959 vide an improved housing for a submersible repeater, the housing being arranged to provide an internal pressure substantially equal to the external hydrostatic pressure.

More particularly, it is an object of the invention to provide an improved housing of the above type in which a pressure equalizing mechanism maintains the internal pressure substantially equal to the external hydrostatic pressure and suppresses seepage of water into the housing.

Another object of the invention is to provide a sensitive pressure equalizing mechanism for a housing of the above type and in which volumetric changes in an insulating fluid are compensated and in which protection from water seepage is provided.

A further object is to provide an improved construction for a submersible chamber, capable of protecting electronic equipment contained therein at very great depths of water.

Another object is to produce a combination of equipment capable of greatly increasing the maximum depth of water at which submerged chambers constructed according to other methods can be operated.

Still another object is to secure additional safety of components and reliability of operation in submerged repeaters through increasing the reserve volumetric capacity of expansible members, without increase of size, weight, or complexity of those members.

A further object is to lengthen the average service life of submerged repeaters by providing a more effective means of compensating for the occasional leakage of liquid into the hermetically sealed containers used for housing certain components such as thermionic tubes and switches operated at atmospheric pressure within the chamber.

Other objects and advantages of the invention will be apparent from the following description.

-In accordance with the invention, a submersible chamber containing electronic apparatus and intended for use where subject to changes in temperature and hydrostatic pressure is filled with an electrically insulating fluid, a bellows member being included within the chamber to transmit external pressure changes to the fluid within the chamber and to compensate for voids occurring within the chamber due to temperature changes of the insulating fluid, additional pressure translating means being provided to transmit external pressure variations to the bellows member and to prevent water from reaching the bellows member.

The invention will now be described in greater detail with reference to the appended drawing in which:

Figs. 1, 2 and 3 are views of a submerged repeater housing embodying the present invention;

Figs. 4 and 5 illustrate one pressure equalizing arrangement for the housing of Figs. 1 to 3, constructed in accordance with the invention;

Figs. 6 and 7 illustrate a second form of pressure equalizing arrangement constnlcted in accordance with the invention;

Fig. 8 is a schematic view of a submersible repeater housing and a filling mechanism therefor employing a vacuum pump;

Fig. 9 is a schematic view of an alternative arrangement wherein a pressure pump is shown for filling insulating fluid into the housing; and

Fig. 10 is a schematic diagram showing a further arrangement for filling the repeater housing with insulating fluid, employing a vacuum pump.

Referring now to the drawing and more particularly to Fig. 1, there is shown a front view of a submerged repeater housing H comprising a hollow tank member 10, a cable entrance chamber 11 and a supporting ring 12. The structural elements of housing H are preferably composed of steel. Tank member is provided with an upper flange 13 fastened to a cover plate 14 by bolts such as 15 arranged along the outer edges of flange 13. Flange 13 and cover plate 14 are separated by a gasket 8 made of'a material such as synthetic rubber which resists salt water.

Cover plate 14 forms the bottom of cable entrance chamber 11. Chamber 11 is also provided with a top plate 16 and side plates 17 and 18 shown sectioned. Not shown in Fig. 1 are back and front plates which, together with side plates 17 and 18, serve to protect the cable entrance chamber. Supporting ring '12 is fastened to top plate 16 by means of a pair of nuts 19.

Repeater housing H is supported by two lengths of steel'rope 20 and 21. One end of each length is formed into an eye which is secured to ring 12 by a link member. The other end of each length is spliced to the armor wiresof respective cable sections 22 and 23 in such manner as to provide slack in cable sections 22 and 23 between the splices and the repeater housing. Cable sections 22 and 23 enter the cable entrance chamber through entrance ports in side plates 17 and '18, respectively. The cable armor Wires are returned through peripheral holes about the entrance ports and are fastened to the armor wires outside the ports, thereby providing a rigid mechanical coupling which will minimize strain on the cable conductors.

Cable section 23 is preferably a bicore cable so that a remote sea earth may be provided for the repeating amplifier input. The repeating amplifier output ground is preferably effected on housing H. The two cable conductors from cable section 23 are passed into tank member 10 through water-tight cable entrance glands 24 and 24. In Fig. 1, gland 24 is hidden behind gland 24. The single cable conductor from cable section 22 is passed into tank member 10 through a Water-tight cable entrance gland 25.

In Fig. 2, which is a side view of the repeater housing, there is shown tank member 10, ring 12, flange 13, cover plate 14, top plate 16, side plate 17 and cable section 22. Also shown in Fig. 2 are front and back plates 26 and 27, respectively, which were not illustrated in Fig. 1. No effort is made to make cable entrance chamber 11 Watertight, the enclosing plates being provided only to prevent mechanical injury to the cable conductors and their insulation. As is evident from Figs. 1 and 2, each of plates 17, 18, 26 and 27 is bolted to top plate 16 and to cover plate 14.

In Fig. 3, which is a sectional view of Fig. 1, taken along line 33, there can be seen cable entrance gland 24 which was hidden in Fig. 1. Also shown in Fig. 3 are four apertures 20 which permit entrance of sea Water into a portion of tank member 10. As can be seen from Fig. 3, tank member 10 and cable entrance chamber 11 have generally rectangular cross-sections.

Referring now to Fig. 4, the lower portion of cable entrance chamber 11 and the upper portion of tank member 10 are shown in cross-section. A hollow metal cylinder 30 having flanges at the upper and lower ends thereof is included within tank member 10. The upper flange of cylinder 30 is fastened to coverplate 14 by bolts, a gasket 31 being provided to insure proper sealing. Apertures 28 in cover plate 14 are arranged to admit sea water into the upper end of cylinder 30-. A piston 32 is included within cylinder 30 and 'is arranged to prevent admission of sea water to the lower portion of cylinder 30 and to transmit the hydrostaticpressure to an oil reservoir comprising the lower end of cylinder 30 and a thin-walled cylindrical metallic bellows 33.

The lower flange of cylinder 30 is fastened'to a plate 34=by bolts, a gasket 35 being employed to insure an oiltight seal. A nipple 36 screwed into an opening in plate '34 and into an opening in the top of bellows 33 'provides mechanical support for bellows 33 and serves as a channel for the transfer of oil between the lower portion of cylinder 30 and bellows 33.

As the repeater housing is lowered through water, the increasing hydrostatic pressure exerted on the top of piston 32 causes piston 32 to travel toward the bottom of cylinder 30, thereby applying a substantially equal pressure to the oil in the reservoir. Increasing pressure of oil in bellows 33 causes the walls thereof to diverge, thereby transmitting the pressure to oil within the remainder of tank 10.

The lower portion of tank 10 contains the-desired electronic apparatus, portions of which may be enclosed within small sealed chambers for operation at normal surface pressures. A number of large electronic components, and in particular transformers and oilfilled capacitors, can conveniently be operated in oil at high hydrostatic pressures, the oil providing excellent insulation.

The three cable conductors referred to hereinbefore are passed through glands 24, 24 and 25 and into the lower portion of tank 10 for suitableconnection to the electronic apparatus. A suitable electronic circuit for use in the repeater is shown in the copending patent application of P. H. Wells et al., Serial No. 229,193, filed May 31, 1951. Additional apparatus for inclusion in tank member 10 is illustrated in the copending patent application of F. B. Bramhall et 211., Serial No. 229,191 filed May 31, 1951.

Since the electronic apparatus will not completely fill the lower portion of tank member 10, and since oil has a relatively high volumetric temperature coefiicient of expansion solid, light-weight inert filler material such as pieces of sheet aluminum cut to fit the space, which has a lower volumetric temperature coefficient, may be provided.

To maximize the repeater life span, it is essential that as much air as possible be excluded from tank member 10. For this purpose, it is desirable that every portion of tank member 10 not filled with apparatus or filler material be filled with oil. Any appreciable amount of air within tank member 10 will, because of the compressibility of air, greatly increase the required capacity of the pressure equalizing apparatus. Any oil having suitable insulating qualities could be employed for filling tank member 10. However, capacitor-type mineral oil is preferred for this purpose because of its excellent electrical qualities and because seepage of this type of oil into the interior of capacitive elements will produce a minimum change in the electrical characteristics thereof.

Moisture within tank member 10 will tend to shorten the life of electronic components. For this reason, all components should be thoroughly dried. Apertures A and A in cover plate 14 are provided for evacuating and filling tank member 10. In service, these apertures are closed with suitable plugs.

When the repeater is lowered to its operating position it will be subjected to a temperature drop which may be as large as 40 F. or more. Since most oils suitable for filling tank member 10 have a relatively large volumetric temperature coetficient, 0.00035 per degree F. being a typical value, means must be provided to fill the space left empty as the oil contracts. In addition, any portions of the tank member not initially filled should be filled When the repeater is subjected to hydrostatic pressure. This is accomplished by expansion of bellows 33 due to increasing hydrostatic pressure. If the interior of bellows 33 were filled with sea water, a thin-walled metallic bellows could not conveniently be used because of corrosion problems. However, it is desirable to employ a thin-walled metallic bellows because of its sensitive response to changes in hydrostatic pressure. Providing the tandem arrangement of piston 32 and bellows 33 permits the use of a thin-Walled metallic bellows. The

reservoir of oil contained in the lower portion of cylinder 30 and in bellows 33 should be sufliciently large to permit bellows 33 .to expand sufficiently to compensate for all decreases in volume of oil within tank member 10.

It has been found impractical to construct a piston and cylinder assembly which will completely prevent sea water from getting past the piston. Furthermore, a substantially water-tight fit of piston and cylinder would tend to be relatively insensitive to small changes in hydrostatic pressure. In the arrangement illustrated in Fig. 4, a small amount of sea water seepage past piston 32 will not produce harmful results because the sea water will still be excluded from the portion of tank member containing electronic apparatus. It is evident, however, that cylinder 30, piston 32 and bellows 33 should be constructed of corrosion resistant metal since each will be subjected to the corrosive effects of salt water.

Fig. 5, which is a section taken along line 55 of Fig. 4, shows the plan arrangement of tank 10, glands 24, 24' and 25, cylinder 30 and bellows 33.

For reasons set forth hereinbefore, it is desirable that thin-walled bellows 33 be not subjected directly to sea water. In the arrangement illustrated in Figs. 4 and 5, suitable separation is obtained by using the tandem arrangement of piston 32 and bellows 33. An important advantage of the tandem arrangement is that failure of either the piston or bellows will not disable the repeater. More particularly, excessive seepage of water past piston 32 will not admit sea Water to the electronic apparatus in tank 10. Similarly, a leak in bellows 33 will not allow the oil from tank 10 to escape to the sea.

An alternative arrangement and one which provides a larger oil reservoir for compensating voids in tank member 10 is illustrated in Figs. 6 and 7. Elements in Figs. 6 and 7 corresponding to elements in Figs. 1 through 5 are given like reference characters.

Referring now to Fig. 6, bellows member 33 is supported by nipple 36 screwed into an aperture in cover plate 14. A second bellows member 40 is mounted on cover plate 14. The walls of bellows member 40 should be formed of a material resistant to both oil and sea water. One suitable material is synthetic rubber. Cover plate 14 serves as the bottom member of bellows 40, the synthetic rubber walls being fastened thereto with bolts. A metal plate 41, also fastened to the walls of bellows 40 with bolts, serves as the top of bellows 40. Since bellows 40 is mounted outside tank member 10, bellows 40 will be subjected directly to hydrostatic pressure. Since both bellows 33 and 40 are filled with oil and since they are joined by nipple 36, pressure exerted on bellows 40 will be transmitted to bellows 33 which, in turn, will transmit the pressure to the oil within tank 10.

For mechanical protection of bellows 40, a metal plate 42 is disposed above plate 41 and supported by four metal straps 43, 44, 45 and 46, of which only straps 43 and 44 are visible in Fig. 6, all four being shown in Fig. 7.

In Fig. 6 the connections of the cable conductors of cable 23 to glands 24 and 24 and the connections of the cable conductor of cable 22 to gland 25 have been omitted for clarity. It is evident that cable entrance chamber 11 of Fig. 6 must be larger than cable entrance chamber 11 of Fig. 1 because of the inclusion of bellows 40 in cable entrance 11 of Fig. 6.

Fig. 7 is a section of Fig. 6 taken along line 77 and shows a plan view of the cable entrance and bellows 40.

As in the case of the tandem piston-bellows arrangement of Figs. 4 and 5, failure of either bellows 33 or bellows 40 of Figs. 6 and 7 will not result in admission of sea water to the electronic apparatus of tank 10. An additional advantage of the double bellows arrangement is that virtually no sea water will be admitted to bellows 33 because the synthetic rubber walls of bellows 40 act as an effective gasket.

The procedures pointed out, together with the construction referred to in the foregoing are adequate to provide a satisfactory range of pressure equalizing capacity in reasonable depths of water and under reasonable changes of temperature, a typical situation being 750 pounds per square inch hydrostatic pressure and a typical temperature being 40 F.

Referring to Fig. 8, it is seen that by the use of a vacuum pump 51, a reduced pressure can be attained in chamber 57, when the valve 54 is open, the valve 56 closed, and the valve 61 closed. Indicator 52 consisting of a closed transparent vessel containing fluid and an inlet dip tube, provides a convenient means of observing the progress of evacuation from the size and frequency of the bubbles which appear therein. When a vacuum in the neighborhood of 15 inches of mercury, as shown on gauge 71, has been obtained, regulating valve 63 is opened to introduce dry nitrogen from the flask 62 into the chamber 57. This process, when repeated several times, is eifective in removing air, moisture and moisture vapor from the equipment enclosed in the container. Immediately after the last introduction of nitrogen, pipe 84 is removed, and the opening left in chamber 57 is plugged. When sufiiciently dehydrated, chamber 57 may be connected to container 64 of oil 66 by opening valve 61. Application of vacuum from pump 51 will then cause chamber 57 to fill with oil. It is advantageous to arrest this process at intervals by closing valve 61 and allowing pump 51 to run, so that air confined or trapped in the interstices in the equipment contained in chamber 57 may be expanded and removed while near the surface of the oil without being subjected to hydrostatic pressure from an excessive head of contained insulating oil standing above it in the chamber 57, which would limit the efiectiveness of the pump 51 in removing it. When chamber 57 is filled, valve 54 is closed, valve 61 is closed, pipe 81 removed, and the opening thus left in chamber 57 is plugged. Valves 56 and 61 are then opened, valve 86 closed, and pump 51 is operated, a vacuum being thereby applied to the space enclosed between the bellows 58 and 59, causing bellows 59 to contract, and drawing further oil 66 from container 64 into chamber 57. Pipe 83 connected to chamber 57 may then be removed and the opening plugged, while the oil level at the opening is held constant by the manipulation of valve 86, after which the vacuum previously applied between diaphragms 58 and 59 may be released and the pipe 82 connected thereto removed. The inter-bellows chamber is now filled by pouring oil into it through the opening in the top plate of diaphragm 58 left by the removal of pipe 82, while the upper bellows is distended by a lifting force applied to the top plate, and that opening is then plugged. By this technique air and moisture are removed from the chamber, and the bellows 53 and 59 are suificiently flexed in an outward direction to provide increased volumetric capacity in order to accommodate later contraction due to the pressure of great depths of sea water acting on the contents of the chamber.

Fig. 9 illustrates another method of filling chamber 57 wherein a pressure pump 67 is used to remove insulating oil 66 from the container 64 and apply it under a pressure indicated by gauge 63 through the check valve 68 into chamber 57. Dry nitrogen gas from flask 62 is first applied through regulating valve 63 to the chamber 57 prior to filling the same with oil, and is exhausted therefrom by vacuum pump 91 having valve 93 open and valves 94 and 69 closed, after a slight pressure has been developed in chamber 57, the process being repeated slowly several times. This accomplishes drying of the interior of chamber 57 and removal of air therefrom, as previously explained. When the dehydration and deaeration are completed, pipe 84 is disconnected and the opening thereby left in chamber 57 is plugged. With valve 69 open, and acting as a vent, oil is forced by pump 67 into chamber 57 until it is partly filled. With valve 94 closed, valve 69 closed and valve 93 open, vac uum pump 91 is operated to remove entrapped gases. The last two steps are repeated until chamber 57 is within the cables.

filled. Pipe 92 and valve 69 are then removed and the openings in chamber :57 plugged. Additional oil is supplied by pump-67 until-diaphragm :59 issufliciently compressed. Pump 67 may then be stopped, the piping 85 between it and chamber :57 removed, and the opening therein plugged, while check .valve 68 prevents leakage of oil during that process, and alsoduring any temporary interruptions whichmay occur in the pumping due to breakage or failure of equipment. Thechamberbetween diaphragms 58 and 59 isthen poured full of oil through opening 82 while diaphragm 58 .isdistended .mechanically, and opening 82' is then plugged.

In Fig. is shown an arrangement for filling chamber 57 with insulating oil 66=from container 64, which presents advantages sufficient to renderit the method. of choice. Vacuum pump 51 is connectedto chamber 57 through indicator 52, valve 54 and pipe 74 withgauge 71 attached thereto,-all previously described. After removal of air, moisture, and moisture vaporfrom chamber'57, withtheaid of nitrogen flask-.62, andregulator valve 63, as descn'bedfor Fig. 8,-the pipe 84 is removed, and the opening left thereby in chamber 57.is plugged. The valve'61 is then opened to permit-aninflow of oil 66 from container-64 to chamber 57 as vacuum pump 51 is operated with valve 54 open. Check valve 172 is located at the foot of dip tube 73 in the path ofthis oil, and'closes to prevent its escapefrom the tank 57. At the completion of pumping and filling and the removal of entrapped air, as previously described for Fig. 8, valve 54 is'closed, pipe 74'removed and the opening left thereby in chamber 57 plugged. Valve 56 is then opened and the pump 51 operated to collapse bellows 59, valve .61 remaining open, thereby withdrawing an additional quantity of oil 66 from container 64 into chamber 57. Pipes 76 and 83 are then disconnected and the .openingin chamber 57 left by the removal of pipe -83 is plugged. The inter-bellows chamber 77 is poured full of oil through the opening from which pipe 76 was removed, while bellows 58 is distended by an upwardly applied force to its upper surface. The opening in bellows 58 is then plugged.

It is seen that both bellows 58 and-59 are left in an upwardly flexed condition, providing them withsubstantially full travel available for the compensation of compressive volume changes due to pressure of sea .Water at great depths. Moreover, the provision of checkvalve 72 in the oil dip tube 73 prevents any outflow of oil from occurring due to an accidental or temporary interruption in the operation-of vacuum'pump-51. In addition, when valve 61 and its associated piping 83 is disconnected preparatory to plugging the opening therefor in chamber 57, the level of oil at thatopening is not dependent upon the degree of pressure in tank 57,. but is fixed and stable-such that a plug readily can be inserted in the opening without danger of loss of oil from or of entrance of air into tank 57. Since the-use of vacuum pump 51 is desirable-in order to remove entrapped air from the chamber 57 in any event, the further advantages of the arrangement of Fig. 10 already mentioned are attained without the use of additional pumping equipment.

In Figs. 8 to 10 we have shown means associated with the container by which voids internal to chamber 57 are substantially reduced or eliminated and the deleterious etfects thereof obviated when the chamber is subjected to conditions of high hydrostatic pressure such as occur at depths from 600 fathoms to over 1000 fathoms. It has been found to be advantageous to operate submarine cable repeaters at such greater depthsin order to amplify the incoming signals before they, encounter interference produced by another cable which the operating cable may parallel or cross, for the purpose'of reducing cross-talk or mutual interference between the signal currents traveling Hydrostatic pressures from approximately 1800 pounds to over 3000 pounds per square inch 58 are encountered in such cases and are successfully accommodated hereby.

While the invention has been described in particular embodiments thereof and in particular uses, it is not desired. that it be limited thereto for obvious modifications thereof will occur to those skilledin the art .withoutdeparting fromthe spirit and the scope of theinvention as setforth in the appended claims.

What isclaimedis:

1. A submersible chamber for operating electrical apparatus in locations subjected to changes in temperature and relatively high hydrostatic pressure, comprising a water-tight tank member containing said electrical apparatus and-being filled with an electrically insulating fluid, a thinewalled expansiblebellows member arranged within said tank member, and a pressure translating device having a reservoir connecting with saidbellows member, said reservoir and said bellows member being filled with a liquid, said pressure translating device being subjected to pressures external to said tankmember thereby to apply said pressures to said liquid, changes in pressure of said liquid producing deformation of said bellows member thereby to apply said pressures to said insulating fluid, changes in volumeof said insulating fluid due to said temperature changes being compensated by proportional deformation of said bellows member whereby the pressure of said insulating fluid is maintained substantially equal to the pressure external to said tank member.

2. A submersible chamber for operating electrical apparatus in locations subjected to changes in temperature and relatively high hydrostatic pressure, comprising a water-tight tank member containing said electrical apparatus and being filled with an electrically insulating fluid, a thin-walled expansible bellows member arranged within said tank member, and means for suppressing leakage of water into said bellows member and for substantially equalizing the external and internal pressures on said tank member comprising a pressure translating device having a reservoir connecting with said bellows member, said reservoir and said bellows member being filled with a liquid, said pressure translating device being subjected to pressures external to said tank member thereby to apply said pressures to said liquid, changes in pressureof said liquid producing deformation of said bellows member thereby to apply said pressures to said insulating fluid, changes in volume of said insulating fluid due-to said temperature changes being compensated by proportional deformation of said bellows member whereby the pressure of said insulating fluid is maintained substantially equal to the pressure external to said tank member.

3. A submersible chamber for operating electronic apparatus in locations subjected to changes in temperature and to relatively high hydrostatic pressure, comprising a water-tight tank member containing said electronic apparatus and being filled with an electrically insulating liquid and means for suppressing leakage of water into said tank member and for substantially equalizing the external and internal pressures on said tank member comprising a thin-walled expansible bellows member arranged within said tank member and a pressure translating device having a reservoir connecting with said bellows member, said reservoir and said bellows member being filled with said liquid, said pressure translating device being subjected to pressures external to said tank member thereby to apply said pressures to the fluid within said reservoir and said bellows member, changes in pressure of the fluid within said reservoir and said bellows members producing deformation of said bellows member thereby to apply said pressures to the insulating fluid within said tank member, changes in volume of said insulating fluid due to said temperature changes being compensated by proportional deformation of said bellows member whereby the pressure of said insulating fluid is maintained substantially equal to the pressure external to said tank member.

4. A submersible chamber for operating a repeating amplifier in a submerged portion of a submarine cable circuit, comprising a water-tight tank member containing said amplifier and being filled with an electrically insulating liquid and means for suppressing leakage of water into said tank member and for substantially equalizing the external and internal pressures on said tank member comprising a thin-walled expansible bellows member arranged Within said tank member, a pressure translating device having a reservoir connecting with said bellows member, said reservoir and said bellows member being filled with said insulating liquid, said pressure translating device being subjected to pressures external to said tank member thereby to apply said pressures to the fluid within said reservoir and said bellows member, changes in pressure of said fluid within said bellows member producing de formation of said bellows member thereby to apply said pressures to the insulating fluid within said tank member, changes in volume of said insulating fluid due to temperature changes being compensated by proportional deformation of said bellows member whereby the pressure of said insulating fluid is maintained substantially equal to the pressure external to said tank member.

5. A submersible chamber for operating electrical apparatus in locations subjected to changes in temperature and hydrostatic pressure, comprising a water-tight tank member containing said electrical apparatus and being filled with an electrically insulating fluid, a cylinder disposed within said tank member and having one end thereof exposed to pressure external to said tank member, a thinawalled expansible bellows member arranged within said tank member and having an open end thereof fastened to the other end of said cylinder, and a piston arranged within said cylinder and forming together with said bellows member a reservoir, said reservoir being filled with a liquid, said piston being arranged for longitudinal movement within said cylinder whereby pres- .sures at said one end of said cylinder are transmitted to :said liquid, changes in pressure of said liquid producing deformation of said bellows member thereby to apply said pressures to said insulating fluid, changes in volume of said insulating fluid due to said temperature changes being compensated by proportional deformation of said bellows member whereby the pressure of said insulating fluid is maintained substantially equal to the pressure external to said tank member.

6. A submersible chamber for operating electronic apparatus in locations subjected to changes in temperature and relatively high hydrostatic pressure, comprising a Water-tight tank member containing said electronic apparatus and being filled with an electrically insulating liquid, and means for substantially equalizing the external and internal pressure on said tank member and for suppressing leakage of water into said tank member comprising a cylinder disposed within said tank member and having one end thereof exposed to pressures external to said tank member, a thin-walled expansible bellows member arranged within said tank member and having an open end thereof fastened to the other end of said cylinder and a piston arranged within said cylinder and forming together with said bellows member a reservoir, said reservoir being filled'with said liquid, said piston being arranged for longitudinal movement within said cylinder whereby external pressures at said one end of said cylin der are transmitted to the fluid within said reservoir, changes in pressure of said fluid within said reservoir producing deformation of said bellows member thereby to apply said external pressures to the insulating fluid within said tank member, changes in volume of said insulating fluid due to said temperature changes being compensated by proportional deformation of said bellows member whereby the pressure of said insulating fluid is maintained substantially equal to the pressure external to said tank member.

7. A submersible chamber for operating a repeating amplifier in a submerged portion of a submarine cable ci'r'- cuit, comprising a water-tight tank member containing said amplifier and being filled with an electrically insulating fluid, and means for substantially equalizing the external and internal pressures on said tank member for suppressing leakage of water into said tank member comprising a cylinder disposed within said tank member and having one end thereof exposed to pressures external to said tank member, a thin-walled expansible bellows member arranged within said tank member and having an open end thereof fastened to the other end of said cylinder and a piston arranged within said cylinder and forming together with said bellows member a reservoir, said reservoir being filled with a liquid, said piston being arranged for longitudinal movement within said cylinder whereby external pressures at said one end of said cylinder are transmitted to said liquid, changes in pressure of said liquid producing deformation of said bellows mem-- ber thereby to apply said external pressures to said insulating fluid, changes in volume of said insulating fluid due to temperature changes being compensated by proportional deformation of said bellows member whereby the pressure of said insulating fluid is maintained substantially equal to the pressure external to said tank member.

8. A submersible chamber for operating a repeating amplifier in a submerged portion of a submarine cable circuit, comprising a water-tight tank member containing said amplifier and being filled with an electrically insulat ing fluid, and means for substantially equalizing the external and internal pressures on said tank member and for suppressing leakage of water into said tank member comprising a hollow metallic cylinder disposed within said tank member and having one end thereof exposed to hydrostatic pressures external to said tank member, a thin-walled metallic expansible bellows member arranged within said tank member and having an open end thereof fastened to the other end of said cylinder and a metallic piston arranged within said cylinder and forming together with said bellows member a reservoir, said reservoir being filled with said fluid, said piston being arranged for longitudinal movement Within said cylinder whereby external pressures at said one end of said cylinder are transmitted to the fluid within said reservoir, changes in pressure of the fluid within said reservoir producing deformation of said bellows member thereby to apply said external pressures to the insulating fluid within said tank member, changes in volume of said insulating fluid due to temperature changes being compensated by proportional deformation of said bellows member whereby the pressure of said insulating fluid is maintained substantially equal to the pressure external to said tank member.

9. A submersible chamber for operating electrical apparatus in locations subjected to changes in temperature and relatively high hydrostatic pressure, comprising a water-tight tank member containing said electrical apparatus and being filled with an electrically insulating fluid, a first thin-walled expansible bellows member arranged within said tank member, and a second expansible bellows member arranged without said tank member and connecting with said first bellows member to form a reservoir, said first and second bellows members being filled with a liquid, said second bellows being subjected to pressures external to said tank member thereby to produce deformation of said second bellows member and to apply" said pressures to said liquid, changes in pressure of said liquid producing deformation of said first bellows mem-- ber thereby to apply said pressures to said insulating fluid, changes in volume of said insulating fluid due to said tem-- perature changes being compensated by proportional deformation of said first bellows member whereby the pressure of said insulating fluid is maintained substantially equal to the pressure external to said tank member.

10. A submersible chamber for operating electronic apparatus in locations subjected to changes in temperature and relatively high hydrostatic pressure, comprising a water-tight tank member containing said electronic apparat s nd being filled withan electrically insulating liquid, and means for substantially equalizing the exter'- nal and internalpre sfsures on said tankmember and "for suppressing leakage'of water into said tank member comprising a first thin-walled expansible bellows member" arranged within said tank member and racism expansible bellows member arranged without said tank member and connecting with said first bellows member to form a reservoir, said first and second bellows membersbeing filled with said liquid, said second bellows member being subjectedt o pressures external to said tank member thereby to produce deformation of said second bellows member and toapply said pressures to the fluid in said reservoir, changes pressure of the fluid in said reservoir producing deformation of said first bellows r'n ernber 'thereby to apply said pressures to the insulating fluid within said tank rnember, changes in volume of said insulating fluid due to said temperature changes being compensated by proportional deformation of said first bellows member whereby the pressure of said insulating fluid is maintained substantially equal to thefpressure external to said tank mrb iba v 11. A submersible chamber for operating a repeating amplifier in a submerged portion of a submarine cable cireuit, comprising a water-tight tank member containing said amplifier and being filled with an electrically insulating fluid, and meansfor substantially equalizing the external and internal pressures on said tank member fand for suppressing leakage of water into said tank member comprising a first'thin-walled efipansible bellows member arranged within said tank member and a second expansible bellows member arranged without said tank member and connecting with said first bellows member to form a reservoir, saidfirst and second bellows members being filled with a liquid, said second bellows member being subjected to pressures external to said tank member thereby to produce deformation of said second bellowsmember and to apply said pressures to said liquid,

changes in pressure of said liquid producing deformation of said first bellows member thereby to apply said pressures to said insulating fluid, changes in volume of said insulating fluid due to temperature changes being compensated by'prop'ortional deformation 'of said first bellows member whereby the pressure of said insulating fluid is maintained substantially equaI to the pressure external to said tank member. i

12. A submersible chamber for operating a repeating amplifier in a submerged portion of a submarine cable circuit, comprising a water-tight tank member containing 'said amplifier and being filled with an electrically insulating liquid, and means for substantially equalizing the external and internal pressures on said tank member and for suppressing leakage of water into said tank member comprising a first thin-walled metallic expansible bellows member arranged within said tank member and a second synthetic rubber expansible bellows member arranged without said tank member and connecting with said first bellows member to form a reservoir, said reservoir being filled with said liquid, said second bellows member being subjected to pressures external to said tank member thereby to produce deformation of said second bellows memberand to apply said pressures to the fluid in said reservoir, changes" in pressure of the fluid in said reservoir producing deformation of said first bellows member thereby to apply said pressures to the insulating fluid within said tank member, changes in volume of said insulating fluid due to temperature changes being compensated by proportional deformation of said first bellows member whereby the pressure of said insulating fluid is maintained substantially equal to the pressure external to said tank member. i

References Cited in the file of this patent UNITED STATES PATENTS 1,690,658 Wilson Nov. 6, 1928 1,932,493 Thomson Oct. 31, 1933 2,227,316 Meyer Dec: 31, 1940 2,418,614 Annin Apr. 8, 1947 2,539,310 Martin Jan. 23, 1951 2,659,390 MacLea et al. Nov. 17, 1953 FOREIGN PATENTS 635,541 Great Britain Apr. 12, 1950 

